1. Field of the Invention
This application relates to a heavy vehicle or truck brake system, and more particularly to a low cost compressed air backup system should difficulties be encountered with the primary compressed air reservoir and/or charging system.
2. Discussion of the Art
Conventionally, heavy vehicles or trucks use compressed air for their braking needs. A compressor charges primary and secondary reservoirs. A control valve, such as a foot control valve, regulates the application of the pressurized air from reservoirs to brake chambers associated with the vehicle wheels to effect braking.
As will be appreciated, the secondary reservoir provides a desired redundancy or backup in case the primary reservoir fails or becomes functionally inoperative, or the charging system fails in a manner well know in the art. The secondary reservoir provides a first level of redundancy or backup operation of the air brakes if the primary reservoir fails.
Although not required by regulation, an additional emergency backup system is always desirable. This is particularly true if such a system can be incorporated into the system at low cost and without substantial modification to existing designs.